scholarly journals On the way to continuous cover forest at middle elevations – the question of forest structure and specific site characteristics

2013 ◽  
Vol 59 (No. 10) ◽  
pp. 391-397 ◽  
Author(s):  
L. Bílek ◽  
J. Remeš ◽  
O. Švec ◽  
D. Zahradník
Keyword(s):  
Species Diversity ◽  
Gini Index ◽  
Structural Diversity ◽  
Transformation Process ◽  
Special Focus ◽  
Simpson Index ◽  
Forest Stands ◽  
Site Characteristics ◽  
Evenness Index ◽  
Diameter Differentiation

The transformation process of even-aged forest stands to irregular forest stands on waterlogged sites after 20 years effort was analysed. Data from two 1-ha PRP was analysed with special focus on structural (Shannon Evenness Index, Simpson Index and Gini Index) and species (Shannon Evenness Index and Simpson Index) diversity. Different development on study plots confirmed that the highest structural diversity is not often compatible with the concept of species diversity. On PRP 1 high diameter differentiation has led to lower values of species diversity, while on PRP 2 rather moderate diameter differentiation supported higher species diversity in lower DBH classes. The Gini Index was confirmed to be the best indicator for monitoring the diameter differentiation in the course of stand transformation.

scholarly journals Echinocandins: structural diversity, biosynthesis, and development of antimycotics

2020 ◽  
Vol 105 (1) ◽  
pp. 55-66
Author(s):  
Wolfgang Hüttel
Keyword(s):  
Isotope Labeling ◽  
Current Knowledge ◽  
Complex Structure ◽  
Hydrolytic Stability ◽  
Structural Diversity ◽  
Gene Clusters ◽  
Special Focus ◽  
Key Points ◽  
Invasive Mycosis ◽  
History Of

Abstract Echinocandins are a clinically important class of non-ribosomal antifungal lipopeptides produced by filamentous fungi. Due to their complex structure, which is characterized by numerous hydroxylated non-proteinogenic amino acids, echinocandin antifungal agents are manufactured semisynthetically. The development of optimized echinocandin structures is therefore closely connected to their biosynthesis. Enormous efforts in industrial research and development including fermentation, classical mutagenesis, isotope labeling, and chemical synthesis eventually led to the development of the active ingredients caspofungin, micafungin, and anidulafungin, which are now used as first-line treatments against invasive mycosis. In the last years, echinocandin biosynthetic gene clusters have been identified, which allowed for the elucidation but also engineering of echinocandin biosynthesis on the molecular level. After a short description of the history of echinocandin research, this review provides an overview of the current knowledge of echinocandin biosynthesis with a special focus of the diverse structural elements, their biosynthetic background, and structure−activity relationships. Key points • Complex and highly oxidized lipopeptides produced by fungi. • Crucial in the design of drugs: side chain, solubility, and hydrolytic stability. • Genetic methods for engineering biosynthesis have recently become available.

scholarly journals Structural diversity and regeneration patterns of the Norway spruce (Picea abies (L.) Karst) dominated virgin forest in NNR Zadná Poľana

Beskydy ◽  
2013 ◽  
Vol 6 (2) ◽  
pp. 127-134 ◽  
Author(s):  
M. Saniga ◽  
Miroslav Balanda ◽  
J. Pittner ◽  
S. Kucbel ◽  
P. Jaloviar
Keyword(s):  
Gini Index ◽  
Nature Reserve ◽  
Structural Diversity ◽  
Height Growth ◽  
Forest Stand ◽  
Virgin Forest ◽  
Old Growth Forest ◽  
Tree Generation ◽  
Evans Index ◽  
Structural Indices

The paper analyzes the structural diversity of the spruce dominated old-growth forest in National Nature Reserve (NNR) Zadná Poľana on the series of three permanent research plots (PRP) with the area of 0.5 ha each. The height and diameter diversity as well as the spatial distribution were expressed using standard structural indices (Füldner’s TH and TD index, Gini index, Clark-Evans index). Obtained results confirmed the low structural diversity regardless of the developmental stage of investigated forest. The extensive ungulate browsing retards the height growth of the subsequent tree generation and leads toward to the structural homogenization of the future forest stand.

scholarly journals Analysis of Gastropod Diversity as a Bioindicator of Waters in Situ Ciburuy Padalarang, West Bandung Regency, West Java, Indonesia

2021 ◽  
pp. 10-19
Author(s):  
Erwin Theofilius ◽  
Zahidah Hasan ◽  
Asep Agus Handaka ◽  
Herman Hamndani
Keyword(s):  
Water Quality ◽  
Species Diversity ◽  
Sampling Method ◽  
Diversity Index ◽  
Research Area ◽  
Survey Method ◽  
Gastropod Species ◽  
Evenness Index

This study conducted to determine the water quality of Situ Ciburuy based on the structure of the gastropod community as a bioindicator. The survey method used in this study based on collecting data directly at the research area (purpose sampling method).  For instance, species and density of gastropods were descriptively analyzed, using diversity index and evenes index. For instance, The findings showed that level of water quality in  Situ Ciburuy based on gastropods bioindicators was lightly polluted. That is indicated by the low to moderate diversity of gastropods, which ranges from 1.31-1.98. The Shannon evenness index (0,73-0.95) revealed low gastropod species diversity in Situ Ciburuy, indicating low evenness of gastropod in Situ Ciburuy.

scholarly journals Phytoplankton Community Investigation and Water Quality Assessment of M River in winter in Shijiazhuang City

2021 ◽  
Vol 267 ◽  
pp. 01035
Author(s):  
Ziqi Zhang ◽  
Lei Yang ◽  
Dongxu Han ◽  
Hongyan Shen
Keyword(s):  
Water Quality ◽  
Species Diversity ◽  
Water Body ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Water Quality Assessment ◽  
Species Diversity Index ◽  
Wiener Diversity Index ◽  
Eutrophic Water ◽  
Evenness Index

An investigation of phytoplankton community and water quality for M River was conducted in December 2019.The results showed that 38 species of phytoplankton belonging to 6 phyla and 26 genera were collected. Among them, Bacillariophyta is the richest species, which accounted for 34.21%, followed by Cyanophyta with 26.32% and Chlorophyta with 28.95%. The density of phytoplankton was 63.0*106 inds/L which indicated as eutrophic water body. The highest density was Bacillariophyta, accounting for 51.03%. The Shannon-Wiener diversity index (H’) varied from 1.34 to 2.24, the Margalef Species diversity index (d) varied from 2.71 to 3.85, and the Pielou evenness index (J) varied from 0.38 to 0.67. According to the integrative analysis results of H’, d and J, M River water quality belongs to oligo-polluted, but individual sites belong to meso-polluted.

Effect of pitfall trap depth on epigaeic beetle sampling (Coleoptera: Carabidae and Staphylinidae) in wet forested ecosites in Alberta, Canada

2018 ◽  
Vol 150 (6) ◽  
pp. 813-820
Author(s):  
H.E. James Hammond ◽  
David W. Langor ◽  
Dustin J. Hartley
Keyword(s):  
Species Diversity ◽  
Trap Depth ◽  
Soil Surface ◽  
Organic Soil ◽  
Pitfall Trap ◽  
Pitfall Traps ◽  
Forest Stands ◽  
Soil Layers ◽  
Deep Traps

AbstractThe depth at which pitfall traps were sunk into the ground and the resulting catches of epigaeic Carabidae (Coleoptera) and Staphylinidae (Coleoptera) assemblages in subhygric to hydric ecosites with very deep organic soil layers was investigated in the upper foothills ecoregion of Alberta, Canada. Traps were installed at seven sites, with six surface traps (the pitfall trap lip <5 cm below soil surface) and six deep traps (the pitfall trap lip >20 cm below soil surface) at each site. A total of 5289 beetles representing 75 taxa were collected. There were no significant effects of trap depth on catch. Rarefaction estimates of species diversity were higher in surface pitfall traps for both taxa. The similarity of pooled catches between deep and surface traps was on average 75%, suggesting that both trap types were collecting similar faunas. We found no advantage to using deep pitfall traps in addition to surface traps to sample the epigaeic fauna of wet forest stands and peatlands.

scholarly journals The Influence of Tree Structural and Species Diversity on Temperate Forest Productivity and Stability in Korea

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1113 ◽  
Author(s):  
Juhan Park ◽  
Hyun Seok Kim ◽  
Hyun Kook Jo ◽  
II Bin Jung
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Temperate Forest ◽  
Temperate Forests ◽  
Basal Area ◽  
Stand Density ◽  
Structural Diversity ◽  
Forest Productivity ◽  
Tree Species Diversity ◽  
Positive Effect

Research Highlights: Using a long-term dataset on temperate forests in South Korea, we established the interrelationships between tree species and structural diversity and forest productivity and stability, and identified a strong, positive effect of structural diversity, rather than tree species diversity, on productivity and stability. Background and Objectives: Globally, species diversity is positively related with forest productivity. However, temperate forests often show a negative or neutral relationship. In those forests, structural diversity, instead of tree species diversity, could control the forest function. Materials and Methods: This study tested the effects of tree species and structural diversity on temperate forest productivity. The basal area increment and relative changes in stand density were used as proxies for forest productivity and stability, respectively. Results: Here we show that structural diversity, but not species diversity, had a significant, positive effect on productivity, whereas species diversity had a negative effect, despite a positive effect on diversity. Structural diversity also promoted fewer changes in stand density between two periods, whereas species diversity showed no such relation. Structurally diverse forests might use resources efficiently through increased canopy complexity due to canopy plasticity. Conclusions: These results indicate reported species diversity effects could be related to structural diversity. They also highlight the importance of managing structurally diverse forests to improve productivity and stability in stand density, which may promote sustainability of forests.

Effects of thinning-induced changes in structural heterogeneity on growth, ingrowth, and mortality in secondary coastal Douglas-fir forests

2015 ◽  
Vol 45 (11) ◽  
pp. 1448-1461 ◽  
Author(s):  
Christian Kuehne ◽  
Aaron R. Weiskittel ◽  
Shawn Fraver ◽  
Klaus J. Puettmann
Keyword(s):  
Species Diversity ◽  
Prediction Models ◽  
Structural Diversity ◽  
Structural Heterogeneity ◽  
Variable Density ◽  
Douglas Fir ◽  
Tree Level ◽  
Spatially Explicit ◽  
Individual Tree ◽  
Diversity Measures

Thinning is believed to accelerate the development of late-successional attributes, thereby enhancing stand structural heterogeneity in young, secondary forests. By making use of a large-scale experiment implemented in 40- to 60-year-old coastal Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco) forests, we addressed the following objectives: (i) determine the effect of three thinning treatments on the temporal dynamics (first 11 years after thinning) of key forest structure measures, (ii) evaluate the relationships between spatially explicit structural diversity measures and spatially nonexplicit stand metrics, and (iii) test the relationships between stand structure and observed periodic stand volume growth, ingrowth, and mortality. Treatments consisted of high-density, moderate-density, and variable-density thinnings-from-below, as well as a control. Differences in stand structural heterogeneity between treatments were mostly nonsignificant. However, our results suggest that variable-density stands displayed structural enrichment as tree size and tree species diversity increased throughout the study period as a result of continuous ingrowth of species other than Douglas-fir. Simple spatially nonexplicit metrics could not be used to reliably model spatially explicit structural diversity measures. The inclusion of structural and species diversity measures only rarely improved accuracy of sample plot level growth, ingrowth, and mortality prediction models. Despite the short-term nature of this study, we conclude that variable-density thinning shows promise in increasing structural heterogeneity in young even-aged stands. The inclusion of structural diversity measures in growth and mortality models may be beneficial, but further work is needed to clarify the underlying relationships, particularly at the individual-tree level.

Successional dynamics of community structure and species diversity after clear-cutting of faxon fir (Abies faxoniana) forest stands

2014 ◽  
Vol 34 (13) ◽  
Author(s):  
缪宁 MIAO Ning ◽  
周珠丽 Zhou Zhuli ◽  
史作民 SHI Zuomin ◽  
冯秋红 FENG Qiuhong
Keyword(s):  
Community Structure ◽  
Species Diversity ◽  
Forest Stands ◽  
Abies Faxoniana ◽  
Clear Cutting

Molluscs Diversity in Coastal Ecosystem of South Biak, Papua

2017 ◽  
Vol 2 (1) ◽  
pp. 25 ◽  
Author(s):  
Ludi Parwadani Aji ◽  
Andriani Widyastuti
Keyword(s):  
Species Richness ◽  
Community Structure ◽  
Sampling Method ◽  
Diversity Index ◽  
Similarity Index ◽  
Coastal Areas ◽  
Seagrass Beds ◽  
Simpson Index ◽  
Transect Line ◽  
Evenness Index

Coastal areas of Biak Island consist of three major ecosystems: the mangrove, seagrass beds, and coral reefs where a variety of molluscs live. Mollusc diversity in South Biak waters was investigated in September 2011. The observation was conducted at 4 locations, i.e. Paray, Ambroben, Yenures, and Sorido with 2 stations at each location. The study aimed to obtain information on the diversity and community structure of the benthic molluscs (gastropods and bivalves) on the coastal areas of South Biak waters. Sampling method applied was quadrate-transect line in intertidal areas from inshore to offshore. The molluscs (epifauna and infauna) found inside the quadrate-transect were counted and identified. The result showed high benthic mollusc diversity with a total of 94 species, consisting of 75 species of gastropods and 19 species of bivalves. The most widespread gastropod found in all stations was Nassarius sp., while for bivalves was Tellina sp. The highest value of diversity index (H) was 2.96 found in Paray 1 and the lowest was 0.58 in Yenures 1. The Evenness index (E) and Simpson index (D) ranged from 0.27 to 0.96 and from 0.06 to 0.72 respectively. Species richness (d) ranged from 2.89 to 6.84 and similarity index from 3.90 to 42.40.  

The marginal cost of structural diversity of mixed uneven-aged hard maple forests

2002 ◽  
Vol 32 (4) ◽  
pp. 616-628 ◽  
Author(s):  
Shashi Kant
Keyword(s):  
Growth Model ◽  
Acer Saccharum ◽  
Marginal Cost ◽  
Structural Diversity ◽  
Shannon Index ◽  
Forest Stand ◽  
Simpson Index ◽  
Southern Ontario ◽  
Theoretical Concepts ◽  
Size Diversity

Theoretical concepts pertaining to the marginal cost (MC) of the structural diversity of a forest stand are developed. A matrix growth model is estimated for mixed uneven-aged forest stands of hard maple (Acer saccharum Marsh.) from southern Ontario. The estimated growth model is used to derive the MC equations for the Shannon and the Simpson indices of total structural diversity (TSD), species diversity (SD), and tree-size diversity (TD). The effects of exclusion and inclusion of the opportunity cost (OC) on the MC of the TSD are compared. The contributions of SD and TD to the MC of the TSD are disaggregated. The MCs of TSD, SD, and TD for the Shannon and the Simpson indices are iso-elastic. The elasticity of the MC of the TSD for the inclusion of OC is greater than the elasticity of MC of the TSD for the exclusion of OC. The elasticities of MC of TSD, SD, and TD for the Shannon index are greater than the elasticities of MC of TSD, SD, and TD, respectively, for the Simpson index. The elasticities of MC of SD are smaller than the elasticities of MC of TD, for both indices. However, these results are specific to the hard maple forests of southern Ontario and cannot be generalized. Some general features of MC equations of structural diversity are discussed.

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